Search for solar axions with CsI(Tl) crystal detectors

Abstract

The results of a search for solar axions from the Korea Invisible Mass Search (KIMS) experiment at the Yangyang Underground Laboratory are presented. Low-energy electron-recoil events would be produced by conversion of solar axions into electrons via the axio-electric effect in CsI(Tl) crystals. Using data from an exposure of 34,596 kg.days, we set a 90 % confidence level upper limit on the axion-electron coupling, g(ae), of 1.39x10(-11) for an axion mass less than 1 keV/c(2). This limit is lower than the indirect solar neutrino bound, and fully excludes QCD axions heavier than 0.48 eV/c(2) and 140.9 eV/c(2) for the DFSZ and KSVZ models respectively.